1. Field of the Invention
The invention relates to a device for detecting flaws on a piece by the automatic reading of indications representative of the flaws to be detected given by a liquid which under the action of a radiation of a first wavelength reemits a radiation of a second wavelength.
2. Description of the Prior Art
It is well-known in monitoring methods that flaws in pieces, especially cracks and splits, can be shown by a special liquid which, under the action of a light, generally in the ultraviolet range, reemits a visible light usually located in the yellow-green range of colors. These known methods of visualizing flaws are called sweating or magnetoscopic methods depending on the method used to obtain the visualization of the flaws by the liquid.
These methods permit a convenient visual examination of the pieces to be performed. An automatic examination of the indications given by these methods has likewise already been proposed. To this end, the use of apparatuses is known which are composed of a monochromatic source emitting a fine ultraviolet beam which illuminates the piece to be studied, after being reflected on a separating mirror which reflects only ultraviolet rays and not visible light. The piece reemits a visible radiation which is not deflected by the separating mirror and is picked up by a detector placed in back of the mirror.
It is necessary in such devices to proceed to an analysis along two axes of the surface to be examined, which generally results in moving the piece during the operation and in using a complex detector.